Hi Laurent,
On Thu, Jan 14, 2021 at 01:23:25AM +0200, Laurent Pinchart wrote:
> Hi Jacopo,
>
> Thank you for the patch.
>
> On Wed, Jan 13, 2021 at 07:55:01PM +0100, Jacopo Mondi wrote:
> > The embedded OV490 ISP chip provides a secondary SCCB interface and
> > two GPIO lines to control the connected OV10640 image sensor.
> >
> > Break out the OV10640 initialization from the OV490 initialization and
> > explicitely control the powerdown and reset GPIOs. After the image
>
> s/explicitely/explicitly/
>
> > sensor has been hard reset, implement a more clear handling of the
> > secondary SCCB interface to read the image sensor chip ID.
> >
> > Signed-off-by: Jacopo Mondi <jacopo+rene...@jmondi.org>
> > ---
> > drivers/media/i2c/rdacm21.c | 75 ++++++++++++++++++++++++++++++-------
> > 1 file changed, 61 insertions(+), 14 deletions(-)
> >
> > diff --git a/drivers/media/i2c/rdacm21.c b/drivers/media/i2c/rdacm21.c
> > index 0428e3209463..944009687de5 100644
> > --- a/drivers/media/i2c/rdacm21.c
> > +++ b/drivers/media/i2c/rdacm21.c
> > @@ -30,11 +30,24 @@
> > #define OV490_PAGE_HIGH_REG 0xfffd
> > #define OV490_PAGE_LOW_REG 0xfffe
> >
> > +/*
> > + * The SCCB slave handling is undocumented; the registers naming scheme is
> > + * totally arbitrary.
> > + */
> > +#define OV490_SCCB_SLAVE_WRITE 0x00
> > +#define OV490_SCCB_SLAVE_READ 0x01
> > +#define OV490_SCCB_SLAVE0_DIR 0x80195000
> > +#define OV490_SCCB_SLAVE0_ADDR_HIGH 0x80195001
> > +#define OV490_SCCB_SLAVE0_ADDR_LOW 0x80195002
> > +
> > #define OV490_DVP_CTRL3 0x80286009
> >
> > #define OV490_ODS_CTRL_FRAME_OUTPUT_EN 0x0c
> > #define OV490_ODS_CTRL 0x8029d000
> >
> > +#define OV490_HOST_CMD 0x808000c0
> > +#define OV490_HOST_CMD_TRIGGER 0xc1
> > +
> > #define OV490_ID_VAL 0x0490
> > #define OV490_ID(_p, _v) ((((_p) & 0xff) << 8) | ((_v) & 0xff))
> > #define OV490_PID 0x8080300a
> > @@ -42,12 +55,22 @@
> > #define OV490_PID_TIMEOUT 20
> > #define OV490_OUTPUT_EN_TIMEOUT 300
> >
> > +#define OV490_GPIO0_RESETB 0x01
>
> Shouldn't this be named just OV490_GPIO0 ? The fact that it's connected
> to the RESETB signal of the OV10640 is board-specific, not an OV490
> intrinsic property.
>
> BIT(0) ?
>
> > +#define OV490_SPWDN0 0x01
>
> Same here.
>
Correct, I'll fix...
> > +#define OV490_GPIO_SEL0 0x80800050
> > +#define OV490_GPIO_SEL1 0x80800051
> > +#define OV490_GPIO_DIRECTION0 0x80800054
> > +#define OV490_GPIO_DIRECTION1 0x80800055
> > +#define OV490_GPIO_OUTPUT_VALUE0 0x80800058
> > +#define OV490_GPIO_OUTPUT_VALUE1 0x80800059
> > +
> > #define OV490_ISP_HSIZE_LOW 0x80820060
> > #define OV490_ISP_HSIZE_HIGH 0x80820061
> > #define OV490_ISP_VSIZE_LOW 0x80820062
> > #define OV490_ISP_VSIZE_HIGH 0x80820063
> >
> > -#define OV10640_ID_LOW 0xa6
> > +#define OV10640_ID_HIGH 0xa6
> > +#define OV10640_CHIP_ID 0x300a
> > #define OV10640_PIXEL_RATE 55000000
> >
> > struct rdacm21_device {
> > @@ -306,6 +329,39 @@ static const struct v4l2_subdev_ops rdacm21_subdev_ops
> > = {
> > .pad = &rdacm21_subdev_pad_ops,
> > };
> >
> > +static int ov10640_initialize(struct rdacm21_device *dev)
> > +{
> > + u8 val;
> > +
> > + /* Power-up OV10640 by setting RESETB and PWDNB pins high. */
> > + ov490_write_reg(dev, OV490_GPIO_SEL0, OV490_GPIO0_RESETB);
> > + ov490_write_reg(dev, OV490_GPIO_SEL1, OV490_SPWDN0);
> > + ov490_write_reg(dev, OV490_GPIO_DIRECTION0, OV490_GPIO0_RESETB);
> > + ov490_write_reg(dev, OV490_GPIO_DIRECTION1, OV490_SPWDN0);
> > + ov490_write_reg(dev, OV490_GPIO_OUTPUT_VALUE0, OV490_GPIO0_RESETB);
> > + ov490_write_reg(dev, OV490_GPIO_OUTPUT_VALUE0, OV490_SPWDN0);
> > + usleep_range(3000, 5000);
>
> So the OV490 firmware doesn't handle this ?
>
Do you mean the delay or the reset of the ov10640 ?
I need the delay here otherwise reading the ov10640 id fails below.
Same for the reset :)
About reset, it seems it does not... The ov490 settings are loaded
from an EEPROM but I don't know what it content is, maybe it's just
about the imaging-related settings ?
> > +
> > + /* Read OV10640 ID to test communications. */
> > + ov490_write_reg(dev, OV490_SCCB_SLAVE0_DIR, OV490_SCCB_SLAVE_READ);
> > + ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_HIGH, OV10640_CHIP_ID >> 8);
> > + ov490_write_reg(dev, OV490_SCCB_SLAVE0_ADDR_LOW, (u8)OV10640_CHIP_ID);
> > +
> > + /* Trigger SCCB slave transaction and give it some time to complete. */
> > + ov490_write_reg(dev, OV490_HOST_CMD, OV490_HOST_CMD_TRIGGER);
> > + usleep_range(1000, 1500);
> > +
> > + ov490_read_reg(dev, OV490_SCCB_SLAVE0_DIR, &val);
> > + if (val != OV10640_ID_HIGH) {
> > + dev_err(dev->dev, "OV10640 ID mismatch: (0x%02x)\n", val);
> > + return -ENODEV;
> > + }
>
> Would it make sense to create an ov490_sensor_read() helper ?
>
While developing this I went and also tested reading other registers
of the ov10640 and I had contradictory results. I'm mostly wondering
if OV490_HOST_CMD_TRIGGER is correct in all cases, as I have some BSP
code that uses a different value.
Can we wait for an helper until we have more users ?
Thanks
j
> > +
> > + dev_dbg(dev->dev, "OV10640 ID = 0x%2x\n", val);
> > +
> > + return 0;
> > +}
> > +
> > static int ov490_initialize(struct rdacm21_device *dev)
> > {
> > u8 pid, ver, val;
> > @@ -349,20 +405,11 @@ static int ov490_initialize(struct rdacm21_device
> > *dev)
> > return -ENODEV;
> > }
> >
> > - /* Read OV10640 Id to test communications. */
> > - ov490_write_reg(dev, 0x80195000, 0x01);
> > - ov490_write_reg(dev, 0x80195001, 0x30);
> > - ov490_write_reg(dev, 0x80195002, 0x0a);
> > - ov490_write_reg(dev, 0x808000c0, 0xc1);
> > -
> > - ov490_read_reg(dev, 0x80195000, &val);
> > - if (val != OV10640_ID_LOW) {
> > - dev_err(dev->dev, "OV10640 ID mismatch: (0x%02x)\n", val);
> > - return -ENODEV;
> > - }
> > -
> > - dev_dbg(dev->dev, "OV10640 ID = 0x%2x\n", val);
> > + ret = ov10640_initialize(dev);
> > + if (ret)
> > + return ret;
> >
> > + /* Program OV490 with register-value table. */
> > for (i = 0; i < ARRAY_SIZE(ov490_regs_wizard); ++i) {
> > ret = ov490_write(dev, ov490_regs_wizard[i].reg,
> > ov490_regs_wizard[i].val);
>
> --
> Regards,
>
> Laurent Pinchart
